1. Field of the Invention
The present invention relates to a slicing machine and in particular to an improved design for an adjustably tilting harp used to slice products into exact volumes.
2. Description of the Related Art
While the present invention is useful for slicing products of any material into pieces having exact volumes, it is of particular importance in the food industry, and in the cheese industry in particular.
In a traditional setting, cheese has been produced by relatively small manufacturers. The manufacturers would typically cut the cheese manually, and individually weigh each package. This process was improved slightly with mechanical slicers. Yet, each package would still be weighed individually in order to determine the package price. Drawbacks of this approach are plentiful. For example, the process of weighing individual packages is time consuming and labor intensive. Even when mechanical weighers are used, there still is a capital requirement for purchase and maintenance of the weighing machines.
For this or other reasons, tilting harps have been developed. One example is shown in U.S. Pat. No. 6,655,248 to Johnson titled Cheese Cutting. This patent shows a cutter for cutting food into consumer-size chunks. A cutting harp is shown. Blocks of cheese are moved towards and through the harp.
The harp in this patent and in other cutters can be tilted relative the plane of the front of the cheese. This is accomplished by having an actuator adjust the angle of the harp relative the front of the cheese.
One drawback of this configuration is that it is very difficult to use a single ram to cut all the way through the cheese, especially when the harp is used in a relatively large angularly adjusted position. Instead, the ram would contact the wires near the bottom prior to pushing the top of the cheese through the harp. This is disadvantageous as additional processes are required to complete the process of cutting of the cheese. This problem is exacerbated as the angle of the tilting harp increases.
An additional drawback of this arrangement is that the angle of the harp cannot be adjusted during the middle of a cutting cycle. This is demonstrated in the Johnson patent, as weight to volume ratios are calculated after a cut, and the harp is adjusted for the next cycle. A drawback of this and other approaches is that excess product can be added to each package where until the dimensions of each cut are correct. While this may be preferable to consumers, such a result adversely affects the manufacturers.
A further drawback of this arrangement is that the force of the cheese passing through the harp places a force against harp actuator that controls the angle of the harp. Over time, the forces can shorten the lifespan of the actuator resulting in premature failure of the machine.
Thus there exists a need for a cutting machine that solves these and other problems.